Simplify popover=hint behaviours & related spec fixes by jakearchibald · Pull Request #12345 · whatwg/html

jakearchibald · 2026-04-08T13:45:02Z

Commit message:

Simplify popover=hint behaviors

- Showing a hint popover doesn't hide auto popovers.
- Showing a hint popover hides non-parent hint popovers.
- Clicking outside popovers consistently hides them.
- Hiding an auto popover does not hide unrelated hint popovers.
- Showing an auto popover as a child of a hint popover downgrades the auto popover to a hint.
- Showing a popover during the show or hide of another popover is no longer allowed.

At least two implementers are interested (and none opposed):
- Mozilla
- Google
Tests are written and can be reviewed and commented upon at:
- Implement new/revised popover=hint behavior web-platform-tests/wpt#59237
Implementation bugs are filed:
- Chromium: https://crbug.com/499019927 (Also, PRs are already up.)
- Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=2034661
- WebKit: Not required. This will be picked up with general popover hint work.
Corresponding HTML AAM & ARIA in HTML issues & PRs: Not required.
MDN issue is filed: Not required.
The top of this comment includes a clear commit message to use.

(See WHATWG Working Mode: Changes for more details.)

Fixes #12304.

Fixes #12346.

Fixes #12355.

Fixes #12356.

Add stuff to infra & use it
Decide on & spec auto-in-hint behaviour
Decide on & spec what happens with popovers shown during beforetoggle-hide.
Review new tests & add more if needed
Apply wrapping

/form-elements.html ( diff )
/infrastructure.html ( diff )
/interactive-elements.html ( diff )
/popover.html ( diff )

jakearchibald · 2026-04-08T14:01:09Z

I'll sort out the wrapping after reviews & changes.

lukewarlow · 2026-04-08T14:14:41Z

Btw https://github.com/domfarolino/specfmt is quite useful for the wrapping.

jakearchibald · 2026-04-08T15:20:38Z

@lukewarlow haha your deleted comment did reveal a bug! It wasn't the return false that was wrong, but I was missing a return true.

jakearchibald · 2026-04-08T15:29:29Z

Edit: I've broken this out into #12355

av1.mp4

@mfreed7 sorry for another video, but I don't think I'd be able to describe it well. What do you see as the intended behaviour here?

https://random-stuff.jakearchibald.com/bug-repros/popover-show-on-hide-warning/ - here's the demo page.

Edit: I'm not convinced my spec totally solves this either, as hiding a popover hides child popovers, which would include the new ones added, and they'd be hidden with events. Maybe.

jakearchibald · 2026-04-09T12:00:41Z

@mfreed7 can you create a PR for your tests so far?

For whatwg/html#12345.

keithamus · 2026-04-10T09:04:38Z

+       <span>"<code>InvalidStateError</code>"</span> <code>DOMException</code>.</p></li>
+
+       <li><p>Return false.</p></li>
+      </ol>


jakearchibald · 2026-04-24T00:14:46Z

@mfreed7 a lovely bit of teamwork! I'm happy for this to land if you are?

mfreed7 · 2026-04-24T15:53:38Z

@mfreed7 a lovely bit of teamwork! I'm happy for this to land if you are?

Totally agree - thanks for raising these issues, explaining them so clearly, and then working through the solutions. This feature got better/cleaner as a result.

LGTM to land this.

This patch updates the popover implementation to align with recent HTML spec changes, specifically regarding reentrancy protection and nested popover types. See the conversation in the spec PR: whatwg/html#12345 1. Strict Reentrancy Protection: Documents now maintain a `popover_showing` boolean and a `popover_hiding_nesting_count` integer to prevent concurrent popover toggles. If `showPopover()` is called while a popover is actively showing or hiding, a `DOMExceptionCode::kInvalidStateError` is immediately thrown. Stack-allocated `ScopedPopoverShowing` and `ScopedPopoverHiding` RAII helpers have been added to safely manage this state during `ShowPopoverInternal` and `HidePopoverInternal`. 2. Downgrading `popover=auto` to `popover=hint`: Previously, attempting to open an `auto` popover nested inside a `hint` popover threw an `InvalidStateError`. The spec now dictates that the `auto` popover should be permitted to open but with its effective type downgraded to `hint`. `ShowPopoverInternal` has been updated to omit the exception and coerce the incoming popover into the `hint_stack` so it appropriately assumes hint light-dismissal behaviors. Check invariants in `HideAllPopoversUntil` have been relaxed to handle this downgraded state safely. Tests in `external/wpt/html/semantics/popovers` have been updated to reflect the new expected behaviors. Bug: 499019927 Change-Id: Ibd6af063310585b9044de63a06e36ffd79d011d4 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7787494 Auto-Submit: Mason Freed <masonf@chromium.org> Reviewed-by: Joey Arhar <jarhar@chromium.org> Commit-Queue: Mason Freed <masonf@chromium.org> Cr-Commit-Position: refs/heads/main@{#1620601}

Co-authored-by: Copilot <copilot@github.com>

jakearchibald · 2026-04-27T22:57:14Z

@annevk looks like we're happy for this to land unless there's anything I'm missing?

There have been a few changes since you last reviewed (sorry), in case you want to review again.

(omg @domfarolino thanks so much for specfmt)

annevk · 2026-04-28T18:25:04Z

@jakearchibald OP appears incomplete. Note that after each edit (including checking a checkbox so best to not use the UI for that) you have to wait for the bot to update it as it will overwrite you otherwise. Also a bit unclear what the status of the tests is.

jakearchibald · 2026-04-29T13:40:54Z

@mfreed7 are the tests complete?

@annevk aside from the tests (waiting for @mfreed7's feedback), I've updated the OP.

mfreed7 · 2026-04-29T15:20:17Z

@mfreed7 are the tests complete?

This comment (#12345 (comment)) is still the state of things. I've left reply comments on the first PR, and the second two are still queued up in Chromium's infra waiting to be uploaded.

As far as I'm concerned, yes, the new WPTs are all good. But I'm biased - I wrote them. Perhaps it'd be best to land all three of those PRs (which given the review hangups will likely take days) as-is, and then we can sort out any nits about the resulting state of tests?

See this discussion for more context: whatwg/html#12304 whatwg/html#12345 This CL implements a simplified behavioral model for popover=hint and popover=auto, cleanly separating the autoRootedPopoverStack from the hintRootedPopoverStack and introducing a `hintStackParent` to track where the hint stack branches off the auto stack. The new behavior resolves the following inconsistencies (gated behind the `PopoverHintNewBehavior` experimental runtime flag): 1. Opening a hint popover will not hide unrelated auto popovers. 2. Opening a hint popover closes only other non-ancestor hint popovers. 3. Clicking outside consistently closes both auto and hint popovers. 4. Hiding an auto popover closes only its child popovers. 5. Opening an auto popover inside a hint popover is disallowed and will fail. A new WPT test (`popover-hint-hierarchy.html`) is added to explicitly assert these 5 rules, and existing popover WPTs are updated to reflect the new behavior. A virtual test suite (`popover-hint-old-behavior`) is also added to continue testing the legacy behavior. I'm not sure how to best handle the changed tests (and I guess the new test too) in the context of a spec PR that is forthcoming. I'd like to be able to publish (as a WPT PR at least) the changes, to help with the PR effort. Suggestions appreciated. A note about the diff: I made all of the feature flag checks look like `if (!feature enabled) {` in the hopes that the old code would show as unchanged in the diff, but gerrit's diff algorithm isn't great. It's at least a little better like this than if I put the new code first, so I left it. Bug: 4990199 Change-Id: I41d8d96be71ba60ec5e7aa640c935258d1e33431 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7727959 Auto-Submit: Mason Freed <masonf@chromium.org> Reviewed-by: David Baron <dbaron@chromium.org> Commit-Queue: David Baron <dbaron@chromium.org> Cr-Commit-Position: refs/heads/main@{#1615186}

@jakearchibald

…ior, a=testonly Automatic update from web-platform-tests Implement new/revised popover=hint behavior See this discussion for more context: whatwg/html#12304 whatwg/html#12345 This CL implements a simplified behavioral model for popover=hint and popover=auto, cleanly separating the autoRootedPopoverStack from the hintRootedPopoverStack and introducing a `hintStackParent` to track where the hint stack branches off the auto stack. The new behavior resolves the following inconsistencies (gated behind the `PopoverHintNewBehavior` experimental runtime flag): 1. Opening a hint popover will not hide unrelated auto popovers. 2. Opening a hint popover closes only other non-ancestor hint popovers. 3. Clicking outside consistently closes both auto and hint popovers. 4. Hiding an auto popover closes only its child popovers. 5. Opening an auto popover inside a hint popover is disallowed and will fail. A new WPT test (`popover-hint-hierarchy.html`) is added to explicitly assert these 5 rules, and existing popover WPTs are updated to reflect the new behavior. A virtual test suite (`popover-hint-old-behavior`) is also added to continue testing the legacy behavior. I'm not sure how to best handle the changed tests (and I guess the new test too) in the context of a spec PR that is forthcoming. I'd like to be able to publish (as a WPT PR at least) the changes, to help with the PR effort. Suggestions appreciated. A note about the diff: I made all of the feature flag checks look like `if (!feature enabled) {` in the hopes that the old code would show as unchanged in the diff, but gerrit's diff algorithm isn't great. It's at least a little better like this than if I put the new code first, so I left it. Bug: 499019927 Change-Id: I41d8d96be71ba60ec5e7aa640c935258d1e33431 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7727959 Auto-Submit: Mason Freed <masonf@chromium.org> Reviewed-by: David Baron <dbaron@chromium.org> Commit-Queue: David Baron <dbaron@chromium.org> Cr-Commit-Position: refs/heads/main@{#1615186} -- Apply suggestion from @jakearchibald Co-authored-by: Jake Archibald <jaffathecake@gmail.com> -- Undo changes to this file -- Spaces -- Apply suggestion from @jakearchibald Co-authored-by: Jake Archibald <jaffathecake@gmail.com> -- wpt-commits: cf48cdceb7740ad09f521fb72b259d51cbb3f489, 36834da0c9a8370330208d84eed5abe092c11f11, b4d10cb3e66c1598e2f02a8d7106d3b34587b777, d1ee0b8ac21c4986aa60ef465e530ef0b76e7546, 7c5c87139d8080facb2095438372aa003b15e1f1 wpt-pr: 59237

jakearchibald added 4 commits April 8, 2026 13:45

Show popover fixed

04c3483

The rest of the owl

f4714ea

No need to set hideUntil to document

3bca74f

Another document set

dc41ca8

jakearchibald commented Apr 8, 2026

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jakearchibald marked this pull request as ready for review April 8, 2026 14:01

jakearchibald requested review from keithamus, lukewarlow and mfreed7 April 8, 2026 14:01

Missing return true

4518fd0

jakearchibald mentioned this pull request Apr 8, 2026

What should happen if you open an auto popover 'within' a hint popover? #12346

Closed

annevk reviewed Apr 9, 2026

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This was referenced Apr 9, 2026

Add list slice whatwg/infra#706

Merged

Add list reverse whatwg/infra#707

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jakearchibald commented Apr 9, 2026

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jakearchibald added 5 commits April 9, 2026 11:38

Minor changes

e345ff0

Hint first, and make it clear the conditions are exclusive

8f4f8fd

Actually remove the TODO lol

31a54ee

Create algo for closing hint then auto popovers

afc6003

Fixing silly mistakes

d2fd3f5

jamesnw mentioned this pull request Apr 9, 2026

Update popover=hint to match spec changes oddbird/popover-polyfill#275

Open

keithamus mentioned this pull request Apr 9, 2026

Should the popoverList in "hide popover stack until" and "close entire popover list" be dynamically updated? #11007

Open

annevk pushed a commit to whatwg/infra that referenced this pull request Apr 10, 2026

Add list reverse

7f8c8ee

For whatwg/html#12345.

Don't hide autos if endpoint is in the hint stack

657f638

keithamus reviewed Apr 10, 2026

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mfreed7 reviewed Apr 24, 2026

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jakearchibald and others added 2 commits April 27, 2026 18:52

Correct handling of throw

c6a01ba

Co-authored-by: Copilot <copilot@github.com>

Wrap

d70b0a8

keithamus reviewed May 5, 2026

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Fix case where "showing popover" would be left true

61e7dfc

lukewarlow reviewed May 13, 2026

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lukewarlow reviewed May 13, 2026

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lukewarlow reviewed May 13, 2026

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lukewarlow reviewed May 13, 2026

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lukewarlow reviewed May 13, 2026

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jakearchibald and others added 7 commits May 13, 2026 17:20

Responding to AI feedback

6c6d1a3

Update wrapping

642c567

nits

a05511f

Fix regression in validity check

6cf279d

Fix wrapping

337bc8e

more nits

8ffd53b

more nits

9f36339

annevk merged commit 59e3d96 into main May 14, 2026
2 checks passed

annevk deleted the jakearchibald/popover-hint-simpler-behaviours branch May 14, 2026 09:37

jakearchibald mentioned this pull request May 14, 2026

Move popover=hint to partial given new spec mdn/browser-compat-data#29676

Open

jonathan-j-lee mentioned this pull request May 15, 2026

Fix a bug in new popover=hint stacking behavior, and update tests web-platform-tests/wpt#59915

Open

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